Infectious Disease Compendium

Aphthous ulcers


Look in the mouth. Painful superficial ulcers, aka canker sores.

Epidemiologic Risks

Life. Up to 2/3 of people will get them in a lifetime. They tend to start in childhood and fade over time. They are non-contagious, non-infectious, and not an STD.


Who knows for sure, there are a lot of alleged reasons for idiopathic oral ulcers. Causes of the non-idiopathic variety of mouth ulcers include herpes, histoplasmosis. If it is painless, think syphilis.

Empiric Therapy

AIDS patients, who can get large aphthous ulcers, topical and systemic steroids may be of help as can thalidomide 100-200 mg q.d. for up to six weeks.

In normal people, topical steroids.



Curious Cases

Relevant links to my Medscape blog

Starts as one diagnosis. Turns out to be another

Last Update: 05/07/18.